In a dielectric barrier discharge lamp, a discharge gas is excited based on the gas discharge theory to convert electric energy into light energy. Aforementioned discharge gas may be an inert gas, such as Xe, Ar, or Kr, or a halogen gas, such as F2 or Cl2. In a dielectric barrier discharge lamp, an AC voltage can be applied to different discharge gases through a plurality of electrodes, and the different excited discharge gases can generate light beams of different wavelengths. Accordingly, the dielectric barrier discharge lamp can be used for many different purposes. For example, a dielectric barrier discharge lamp filled with Xe can generate a light beam having a wavelength of 172 nm. Because this light beam can dissolve organic compounds on electronic parts, the dielectric barrier discharge lamp can be used for cleaning electronic parts. In other words, besides being used as illuminating light source, dielectric barrier discharge lamps are also broadly used in the industrial, agricultural, medical, and scientific fields.
In a dielectric barrier discharge lamp, because an AC voltage is applied to the discharge gas, so as to generate the illuminating light beam, by using electrodes, it is very important to provide a uniform light source through the design of the electrodes. Conventionally, the electrodes are usually disposed on inner and outer surfaces of a double-layered lamp tube, and an AC voltage is applied to the electrodes for stimulating the discharge gas between the electrodes to generate the illuminating light beam. However, this technique offers a high cost. In addition, as for a single-layered lamp tube, while placing an inner electrode in a lamp tube, if both ends of the electrode are fixed to the lamp tube, the metal electrode may be deformed or twisted when it is heated and expands. As a result, unsatisfactory illumination uniformity may occur or the dielectric barrier discharge lamp may be damaged. Thereby, there is still a lot of space for improvement in the present design of dielectric barrier discharge lamp.